地区电力系统供电能力评估

随着电力系统规模不断增大、运行特性趋于复杂及用电负荷逐步增长,电力系统供电能力评估研究逐步由较大的省级电力系统延伸到相对较小的地区电力系统。地区电力系统供电能力能够反映该系统的可靠性、供电薄弱环节和与其它地区电力系统间的互联强度,可以在相当程度上据此来判断电力系统结构的优劣。传统的地区电力系统供电能力评估方法在计算时有可能遗漏一些重要的风险状态,如此得到的计算结果可能会有较大的误差。在此背景下,将地区电力系统供电能力计算描述为非线性有约束优化问题。之后,引入了基于支路开断分布因子的N-1预想事故分析方法,并采用差异进化算法来求取地区电力系统最大供电能力。最后,采用广东电力系统的两个实际算例来说明所提出的模型和方法的可行性与有效性。     

Statistical Independence as Linear Independence

A contingency table summarizes the conditional frequencies of two attributes and shows how these two attributes are dependent on each other. Thus, this table is a fundamental tool for pattern discovery with conditional probabilities, such as rule discovery. In this paper, a contingency table is interpreted from the viewpoint of granular computing. The first important observation is that a contingency table compares two attributes with respect to the number of equivalence classes. The second important observation is that matrix algebra is a key point of analysis of this table. Especially, the degree of independence, rank plays a very important role in extracting a probabilistic model from a given contingency table.     

物理试卷统计分析与评价模型

提出了一个对物理试卷的综合评价体系，以客观评价学生的实际学业水平和教学效果，促进物理教学工作改革。     

The Mother-Infant Relationship in Single, Cohabiting, and Married Families: A Case for Marriage?

Single-mother, cohabiting 2-parent, and married 2-parent families with infants were compared on maternal and infant behavior, Home Observation for Measurement of the Environment (HOME) scores, and infant's security of attachment. Married mothers and their infants demonstrated more positive behavior and received higher HOME scores when the infant was 6 and 15 months old than did their cohabiting and single counterparts. Married families were also better off than single and cohabiting families on several demographic, parent personality, financial, and social context measures. Single and cohabiting families were similar across most measures. Selection variables (maternal age, ethnic group, and education) explained much, but not all, of the family structure differences in the mother-infant relationship and the HOME. Maternal psychological adjustment, attitudes about child rearing, income, and social support explained little of the family structure variation, suggesting that characteristics that preceded marriage and conception were important determinants of family structure differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and the Detection of Contingency in Causal Learning.

Young and older participants' ability to detect negative, random, and positive response-outcome contingencies was evaluated using both contingency estimation and response rate adaptation tasks. Age differences in contingency estimation were consistently greater for negative than positive contingencies, and these differences, though still present, were smaller when response rate adaptation was used as the measure of contingency learning. Detecting causal contingency apparently becomes more difficult with age, especially when an oven numerical estimate of contingency must be provided and when the relationship between a causal event and an outcome is negative. A model that incorporates features of both associative and rule-based approaches to contingency learning (e.g., P. C. Price & J. F. Yates, 1995; D. R. Shanks, 1995) provides the best explanation for this pattern of findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Comparative Study of Group Contingencies and Randomized Reinforcers to Reduce Disruptive Classroom Behavior.

The present investigation employed an alternating treatments design to (1) examine the efficacy of group contingencies in the reduction of disruptive behavior, and (2) compare the effects of independent, interdependent, and dependent group contingencies in the reduction of disruptive behavior in adolescent males identified with serious emotional disturbance. Disruptive classroom behavior has been associated with both decrement inacademic performance and increased risk for antisocial behavior. Although research findings have suggested that group contingencies are efficacious in reducing disruptive behavior, the data remain inconclusive regarding which group contingency (interdependent, dependent, and independent) is most effective. Results suggest that a clear superiority among the group contingencies was not evidenced. However, all were dramatically effective in the reduction of classroom disruptive behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A MULTIMODAL BIOMETRIC IDENTIFICATION SYSTEM USING COMPRESSED FINGER IMAGES

Finger image recognition remains one of the most prominent biometric identification methods. However, storage of finger databases needs allocation of huge secondary storage devices. In addition, there has been limited success in obtaining a satisfactory system due to the complexity of the problem. In this article, a low-cost, high-speed, multimodal biometric identification system trained with compressed finger images is presented with the objective to increase the overall matching confidence level. For this, three finger images of the left or right hand, or both, for one person are matched and the output decision is combined. A prototype optical-based finger-data acquisition system using the CCD (charge coupled device) digital still camera is adopted to capture a complete impression of finger area required for accurately identifying an individual. The acquired images then are compressed with a Coif5 wavelet packet-based scheme to increase the overall performance and eliminate bulk storage requirements. The finger image features are extracted with an adaptive neural network for the implementation of a three-finger multimodal system to achieve a peak identification rate of 100% (99.4% on average) in 0.15s for a database of 50 persons and 450 test images.     

建设工程计价价差预备费测算方法讨论

通过对CECA-GC1-2007建设项目投资估算编审规程可行性研究阶段投资估算中价差预备费计算公式进行讨论,描述了该公式所采用的数学模型及其推导过程,对投资者增进对该公式的理解,更好的把握投资估算的方法起到了有益的作用。     

Relations between in-treatment and follow-up abstinence among cocaine-dependent homeless persons in three clinical trials.

Clinical trials with cocaine-dependent outpatients have found a strong relation between in-treatment and follow-up abstinence, and the strength of this relation is constant across treatment conditions with variable efficacy in generating abstinence. The authors conducted secondary analyses of data from 3 clinical trials to determine whether this relation generalizes to cocaine-dependent homeless persons. The 3 trials (total N = 543) were conducted in a community health care facility for homeless people. The 7 treatment arms across the 3 trials were combinations of day treatment, abstinence-contingent housing, and vocational training. Drug use was measured with urine toxicology testing. Consecutive weeks of abstinence during treatment were strongly related to abstinence at the 12-month follow-up, whether or not missing 12-month data were included in the analysis. The treatment arms differed in their efficacy in generating abstinence, but the relation between in-treatment and follow-up abstinence did not differ across treatment arms. These results replicate earlier reports of these relations and extend them to a population of homeless people. The lack of differences between treatment arms in the in-treatment–follow-up abstinence relation implies that that relation is independent of the treatment-specific intervention components that generate group differences in abstinence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一种快速求解大规模安全约束最优潮流的多核并行方法

针对传统安全约束最优潮流计算方法占用内存大、计算时间长的问题,提出了一种多核并行安全约束最优潮流算法。由正常运行状态检验预想故障状态,选取少量严重故障逐步修正正常运行状态,直到所有状态都得到满足。多核并行技术用于实现算法从高到低层次的高效率整体并行,以提高计算速度。其中,采用有向无环图并行数值分解算法实现正常运行状态修正过程的细粒度并行,并根据算法特性,直接实现预想故障状态检验过程的粗粒度并行。某省-3301节点系统(预设693个故障)等3个系统的计算结果表明:随着系统规模的扩大,所提方法占用内存不足传统方法的1%,且计算速度可快于传统方法三个数量级以上。